体验Stream流

package LambdaTest.LambdaTest06;

import java.util.ArrayList;

/**
 * FileName: StreamDemo
 * Author:   lps
 * Date:     2022/4/9 21:00
 * Sign:刘品水 Q：1944900433
 */
public class StreamDemo {
    public static void main(String[] args) {
        ArrayList<String> array = new ArrayList<>();
        array.add("刘品水");
        array.add("刘品火");
        array.add("大张伟");
        array.add("刘一手");
        array.add("刘红");
        array.add("张伟");
        array.add("小张伟");
        ArrayList<String> Liulist = new ArrayList<>();
        for (String s : array){
            if (s.startsWith("刘")){
                Liulist.add(s);
            }
        }
        //System.out.println(Liulist);
        ArrayList<String> ThreeLiulist = new ArrayList<>();
        for (String s:Liulist){
            if (s.length()==3){
                ThreeLiulist.add(s);
            }
        }
        //System.out.println(ThreeLiulist);
        for (String s:ThreeLiulist){
            System.out.println(s);
        }
        System.out.println("==============");

        //stream流来改进
        //filter
        //Stream<T> filter(Predicate<? super T> predicate)
        //返回由该流的元素组成的流，该元素与给定的谓词匹配 这是一个intermediate operation。参数
        // predicate - non-interfering， stateless谓词应用到每个元素以确定它是否应该包括 结果新的流
        //array.stream().filter(s -> s.startsWith("刘")).filter(s -> s.length()==3).forEach(s -> System.out.println(s));

        array.stream().filter(s -> s.startsWith("刘")).filter(s -> s.length()==3).forEach(System.out::println);





    }

}